Lubricating composition



LUBRICATING COMPOSITION Lawrence C. Westcott, Edwardsville, and Howard M.; Lurton, Dow, 111., assignors to Shell Oil Company,

This invention relates to corrosion resistant, extreme pressure lubricants and, more particularly, to mineral United States Patent-O lubricating oil compositions applicable for use as non corrosive, extreme pressure steam turbine lubricants.

It is known that lubricants, such as steam turbine lubricants, are improved with respect to wear and corrosion inhibition by means of sulfurized unsaturated fatty acids and alkenyl-substituted dibasic acids. However,-

with the increasing speeds, pressures, and temperatures and other rigorous service conditions provided by modern industrial equipment, previously known lubricants of this type generally fail due to their inability to meet heavy duty requirements.

Theaddition of known extreme pressure agents, such as chlorine or phosphorus-containing materials, e.g., chlorinated paraffin waxes, organic thiophosphates, etc.,

although effective in increasing the extreme pressure properties of such steam turbine lublicants, in the presence of moisture tend to sludge and cause corrosion due to liberation of corrosive acids such as HCl. Stabilizers, such as arylamines (diphenylamine) or polyalkylene polyamines (triethylene tetramine), are ineffective in inhibiting the sludging or corrosion tendencies of such compositions.

In accordance with the present invention, a non-corrosive, extreme pressure lubricant of superior quality and resistance to hydrolysis is provided by a mineral lubricating oil containing small amounts each of 1) an oil-miscible sulfurized unsaturated fatty acid having at least 10, preferably 18 and more carbon atoms, (2) an oil miscible aliphatic-substituted dicarboxylic acid having at least 10 carbon atoms, (3) a chlorinated parafin tor.

The oil-soluble sulfurized unsaturated fatty acids having at least 10 carbon atoms may be any sulfurized unsaturated fatty acid, such as sulfurized oleic, linoleic, erucic, linolenic, ricinoleic, and ricinelaidic acids. The sulfurization of these fatty acids can be accomplished by reacting the aforementioned unsaturated fatty acids and mixtures thereof with a suitable sulfurizing agent such as sulfur, sulfur chloride, phosphorous polysulfide, mixtures of sulfur and hydrogen sulfide or mixtures of sulfur dioxide and hydrogen sulfide and the like. Suitable reaction temperature and catalysts such as organic amines, iodine, etc., can be used to activate the reaction until the final product contains at least 5%, and preferably from 10% to 30% sulfur in the molecule. A sulfurized oleic acid having a sulfur content of from about 10% to about 25% can be obtained by reacting (under inert conditions) at about 150-180 C. about 1 mol oleic acid with about 1 mol of sulfur for about 4 hours and thereafter purifying the sulfurized acid by filtering through an acid washed adsorptive clay. Another method of sulfurizing oleic acid is by treating the oleic acid with sulfur chloride in the presence of a small amount of water at 120-160 F. for about an hour. The sulfurized prowax, (4) an aromatic amine, and (5)'a metal deactivaduct is diluted with hexane and neutralized with sodium carbonate. The hexane-soluble fraction is removed, the hexane evaporated to recover sulfurized oleic acid having a sulfur content of about 10%.

The oil-soluble saturated or preferably unsaturated aliphatic dicarboxylic acids containing at least 10 carbon atoms in the molecule and at least one carbon atom between the carboxyl groups include C C alkyl or alkenyl, preferably (3 -0 alkyl or C .,C alkenyl dicarboxylic acids, e.g., C -C alkyl succinic, adipic, sebacic acid or suberic acid or acids such as Cpl-C24 alkenyl succinic, glutaric, adipic, pimelic, sebacic, \azelaic, and suben'c acids and mixtures thereof. Typical examples of the preferred acids are G -C alkyl succinic acid or C13-C22 alkenyl succinic, glutaric and adipic acids.

The chlorinated paraflin wax is one having a high content of chlorine of from about 20% to about 60%, preferably about 4050% chlorine. It can be produced by chlorinating the wax by conventional means as described in U.S. Patents 2,682,523 or 2,410,381. Products of this type are commercially available and are sold under the name of Anglamol 40 by Lubrizol Corporation. Anglamol 40 chlorinated paraffin wax has a chlorine content of 43.4%.

The metal deactivator is derived by reacting an arcmatic ortho-hydroxyl aldehyde such as 2-hydroxy benzaldehyde or salicyaldehyde and an alkylene polyamine and derivatives thereof. Examples of these metal deactivators which may be termed di(2-hydroxy benzal)- alkylene polyamines are N,N.-disalicylal-l,2-propylene diamine, N,N-disalicylal-1,2-ethylene diamine, di(2-hydroxy benzal) ethylene diamine, di(2-hydroxy benzal) diethylene triamine, di(2-hydroxy benzal) propylene diamine, etc. The aromatic amines are represented by the formulaRR'NH wherein R and R are the same or different monoor polyaromatic radicals such as diphenylamine, dinaphthylamine, ditolylamine, phenyltolylamine, tolylnaphthylamine, and the like. Mixtures of the metal deactivators and aromatic amines include diphenylamine- N,N'-salicylal-1,2-propylene diamine, diphenylamine-N, N salicylal-l,Z-ethylenediamine, dinaphthylamine-N,N'- salicylal 1,2-propy1enediamine, dipheny1amine-di(2-hydroxybenzal) diethylene triarnine, etc. Mixtures of this type are commercially available from du Pont under the trade name Ortholeum 300 (diphenylamine-metal deactivator having a melting point range of to F.).

Suitable auxiliary anti-oxidant additive combinations foruse in compositions containing the above additives include alkyl phenols. The alkyl phenols include diand tr-ialkyl phenols, e.g., 2,4-, 2,3-, 2,6-, and 3,5-dimyl or dihexylphenol, 2,4-dimethyl-6-tert-buty1 phenol, 2,6- ditert-butyl-4-methyl phenol and mixtures thereof. The alkyl phenols are particularly effective when the phenols are used with amines such as naphthylamine, such as phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, di alpha naphthylamine, di beta naphthylamine and mixtures thereof.

The mineral oil may be selected from a variety of stocks such as parafiinic, naphthenic, and mixed base mineral oils having a viscosity range of from about 40 to about 400 SUS at 100 F., preferably from about 100 to about 200 SUS at 100 F. A typical useful mineral oil is a highly refined mineral lubricating oil (X) having the following properties:

from about 0.001% to about 10%, preferably from about 0.01% to about 5% by weight, and the auxiliary 3 additive combination when used is present in amounts of from about 0.01% to about 2% by weight.

The following examples illustrate compositions of this invention:

Example I Sulfu'rized oleic acid 0.06% wt. C C alkenyl succinic acid 0.015% wt. Chlorinated parafiin wax (43.4% C1) 5% wt. Diphenylamine 0.05% wt. Salicylalamino alkane 0.05% wt. Mineral oil (X) Balance.

Example 11 Sulfurized oleic acid 0.06% wt. C C alkenyl succinic acid 0.015% wt. Chlorinated parafiin wax (43.4% Cl)- 5% wt. Diphenylamine 0.05% wt. N,N-salicylal-1,2-pnopy1ene diamine 0.05% wt. Phenyl-alpha-naphthylamine 0.1% wt. 2,6-ditertbutyl-4methylphenol 0.5% wt. Mineral oil (X) Balance.

Example III Sulfurized oleic acid 0.06% wt. Cur-C13 alkyl succinic acid 0.015% wt. Chlorinated paraflin wax (43.4% C1)... 5% wt. Dinaphthylamine n 0.1% wt. N,N-salicylal-1,Z-propylene diamine 0.1% wt. P11enylealpha-naphthylamine 0.1% wt. 2,6-ditertbutyl-4-rnethylphenol 0.5% wt. Mineral oil (X) Balance.

Example IV Sulfurized ricinoleic acid 0.1% wt. C C alkenyladipic acid 0.02% Wt. Chlorinated paraflin wax (40-50% Cl)..-" 5% wt. Diphenylamine 0.1% wt. N,N-sa1icylal-1,2-propy1ene diann'ne 0.1% wt. Mineral (100 SUS 100 F.) Balance.

Example V Sulfurized linoleic acid H.. 0.1% wt. C -C alkenyl malonic acid 0.02% wt. Chlorinated paraffin wax (4050% Ol) 2.5% wt. Diphenylamine 0.1% wt. N,N-salicylal-1,Z-propylene diamine 0.1% wt. 2,6-ditertbuty-l-4-methylphenol 0.5% wt. Phenyl-alpha-naphthylamine t 0.1% wt. Mineral oil (150 SUS at 100 F.) Balance.

Compositions of the present invention ,(I-V) are 50 of H01 evolution or tendency to coke or darken at temperatures of 450-550 F. and higher. Similar compositions from which the metal deactivator-amine combination omitted are unstable and revolution of HCl is noticeable visually even at temperatures of below 400 F. and extreme darkening and extensive coking oi the oil is noted. Compositions of the present invention when tested for their load-carrying ability in the Ryder Gear Test under MIL-L-17331A specification conditions carry loads higher than that required by this test. However, when the chlorinated panafiin wax or the chlorinated paraflin Wax and the mixture metal tdeactivator-amine are omitted from compositions I-V, such modified compositions tfiail to pass the test.

We claim as our invention:

1. A lubricating oil composition consisting essentially of a major amount of minenal oil and mom about 0.01% to about 5% each of sulfurized oleic acid containing from 10% to 30% sulfur in the molecule, 0 -0 alkenyl succinic acid, chlorinated paraflin wax containing firom 20% to chlorine in the molecule, diphenylamine and N,N-salicylal1,2-propylene diamine.

2. The composition of claim 1 containing from about 0.01% to about 5% each of 2,6-ditertbutyl-4-methylphenol and phenyl-alphanaphthylamine.

3. A lubricating composition having the formula by weight:

Sulfurized oleic acid (1025% S) 0.06%. Cur-C22 valkenyl succinic acid Chlorinated paraifin Wax (43.4% C1) 5%. Diphenylamine 0.05%. N,N-salicylal-1,2-propylene diamine 0.05%. Phenyl-alphawnaphthylamine 0.1%. 2,6-ditertbutytl-4-methylphenol 0.5%. Mineral o'il Balance.

References Cited in the file of this patent UNITED STATES PATENTS 2,133,734 Moser Oct. 18, 1938 2,156,265 Miller et a1. May 2, 1939 2,349,044 123.1111 May 16, 1944 2,351,347 Luten June 13, 1944 2,352,164 et al. June .27, 1944 2,420,953 Hunt May 20, 1947 2,459,718 Barnum :et al. Jan. 18, 1949 

1. A LUBRICATING OIL COMPOSITION CONSISTING ESSENTIALLY OF A MAJOR AMOUNT OF MINERAL OIL AND FROM ABOUT 0.01% TO ABOUT 5% EACH OF SULFURIZED OLEIC ACID CONTAINING FROM 1/% TO 30% SULFUR IN THE MOLECULE, C18-C22 ALKENYL SUCCININC ACID, CHLORINATED PARAFFIN WAX CONTAINING FROM 20% TO 60% CHLORINE IN THE MOLECULE, DIPHENYLAMINE AND N,N-SALICYLAL-1,2-PROPYLENE DIAMINE. 